B.E-B.E Electronics and Tele-Communication Engineering Cryptography(Sathyabama University, Chennai, Tamil Nadu-2010)
Friday, 23 August 2013 02:59Duraimani
(Established under section 3 of UGC Act,1956)
Course & Branch :B.E - ETCE
Title of the Paper :Cryptography Max. Marks :80
Sub. Code :525703/625703 Time : 3 Hours
Date :03/03/2010 Session :AN
PART - A (10 x 2 = 20)
Answer ALL the Questions
1. The given cipher text is “ybpq lc irzh”. Find the plain text when the key is “monoalphabetic cipher” with x = x+3.
2. State the difference between stegnography and cryptography.
3. What are the strengths of DES algorithm?
4. Find the GCD of “2740” and “1760” using Euclid’s algorithm.
5. Write down the principles behind RSA’s secure model.
6. Which formula does the Elliptic curve system use to determine the relationship between public key and private keys within the universe created by an elliptic curve?
7. What is S/MIME?
8. How does IP security offer the authentication and confidentiality services?
9. List the classes of Intruders
10. What is IP address spoofing?
PART – B (5 x 12 = 60)
Answer All the Questions
11. Explain the basic model for network security.
(or)
12. Write short notes on
(a) Play fair
(b) Polyalphabetic ciphers
13. Describe the block cipher models of operation in detail.
(or)
14. Given 10 bit key K = 1010000010 determine K1K2 where
P10 = 3 5 2 7 4 10 1 9 8 6
P8 = 6 3 7 4 8 5 1 0 9
By using SDES key generation method.
15. Perform Encryption / Decryption using RSA algorithm for the following.
P = 3, q=11, e=7, m=5
(or)
16. Users A and B use the Diffie Hellman key exchange technique a common prime q = 11 and a primitive root alpha = 7
(a) if user A has private key XA=3, what is A’s public YA? (2)
(b) If user B has private key XB=6 what is B’s public key YB? (2)
(c) What is the shared secret key? Also write the algorithm (3)
(d) How can the man – in – middle attack be performed in the Diffie Hellman algorithm?
17. Describe the SSL specific protocol handshake action in detail.
(or)
18. Explain the function of Kerberos authentication server.
19. What are the demerits of not using firewall? List the design goals of firewall.
(or)
20. With circuit schematic explain packet filtering router type in firewall.
| Earning: ₹ 3.25/- |
